I am sure this is a random key sequence I used or possibly something I have clicked on but I can not figure out how to make it stop. While typing in Word if I try to use the shift to capitalize a letter or put in a special character it will paste what ever the last thing I have copied is. Any ideas? I have been through a lot of forums looking for answers and have not found any that work. Thank you!

That is strange indeed. Are you certain that it is only by pressing the shift key and before pressing any other key that pasting is occurring? If so, I'm tempted to wonder whether it is a Windows glitch that has been created, perhaps even an accessibility in which case a repair Windows cycle might be helpful. I might also suggest opening the All commands list in Word's keyboard shortcuts (Options/Customize Ribbon/Keyboard shortcuts Customize), and scroll through the various Paste commands to see if a shortcut has been created. Still, Shift is not, to my knowledge, a sufficient command for paste.

fwiw, shift+insert is the old Paste shortcut from what feels like centuries ago …